Not His Problem
by sandersonsister
Summary: Iwaizumi has never really understood what Oikawa's issue with Kageyama was. But it wasn't any of his business. It wasn't like it was his problem...


Iwaizumi was eight when he first learned about soulmates. He had been so excited when his sensei had explained what that odd mark on his body meant. She explained how somewhere in the world, a person that would know them better than anyone, someone that would always be by their side, had a matching mark.

He had known instantly who his soulmate was. He remembered running home, pulling Tooru behind him, until they reached his room. Tooru had been confused, whining the entire way about why wouldn't he slow down?! But he couldn't wait. He closed the door to his room and demanded that Tooru show him his mark. He just knew the two would match! He wouldn't be one of the ones that had to wait years and years, like sensei had said.

But a pool of dread built up when Tooru began to pull up his pant leg. Why would he need to do that to show the mark on his back? Maybe Tooru didn't know what he was talking about. Maybe he was confused…

But no. There, on Tooru's ankle, had been a mark that looked nothing like the one on Iwaizumi.

That was the first night in a long time he cried. And the last.

It hadn't changed anything, not really. Oikawa was still his best friend. Oikawa was the one that knew him best. He was the one that knew Oikawa best. They just weren't soulmates. And it was fine.

And maybe, at first, that had been a lie. But as they grew, as they began focusing on volleyball and Oikawa had grown into his overly big nose, Iwaizumi had known that it was a good thing he and Oikawa weren't soulmates. He loved Oikawa and he always would…but not in the way sensei had described it to him all those years ago. Not in the way his parents loved each other. Oikawa was his best friend and that was all.

It was in their third year of junior high that Iwaizumi came to this realization – and it was also the same year that Oikawa began to act strange. Well, stranger than usual. At first, everything was the same as it had always been. But after Kageyama joined the team, that genius setter that even Iwaizumi could see would pass Oikawa eventually, Oikawa began to do things that even Iwaizumi couldn't explain. The staying after practice and working alone wasn't strange. The pushing himself further than necessary wasn't either. But there were other things…things Iwaizumi couldn't explain.

Like the fact that Oikawa had shown up to his house one afternoon with red eyes and tear tracks on his cheeks. And had refused to tell Iwaizumi what was wrong.

Like how suddenly Oikawa always had something for him to do before he could come to practice, so he was always a little bit later than everyone else.

Or how Oikawa asked the other third years on the team to work with the first years – which had been something Iwaizumi did – because he needed to "practice with my ace, Iwa-chan!"

It was when Iwaizumi stepped in front of Kageyama after the first year had almost got a hand to the face, courtesy of Iwaizumi's best friend, that he knew he needed to do something. "Listen, I know you're upset," Iwaizumi said that night as Oikawa curled up on his bed, an ice pack on his nose. Yeah, Iwaizumi might have hit just a little too hard… "You can't keep doing this. Kageyama is a first year. He still has a long way to go to even match you."

The words seemed to bring a fresh wave of tears from Oikawa. "Bu-but he will. One day. He will pass me and take everything away! I can't let him do that, Iwa-chan! He can't take it away!"

Iwaizumi didn't know what to say. How could Oikawa honestly think that Kageyama would take everything from him? "Oikawa, he isn't going to take everything away. Calm down."

But the tears didn't stop and Iwaizumi found himself pulled onto the bed, his best friend crying against his chest.

After they moved on from junior high, Oikawa seemed to get better. He still practiced too much, still pushed himself too hard, but he was getting better.

Or so Iwaizumi thought.

He had never been so mad, or so worried, as on the day he went to the gym to pull Oikawa home and found him on the ground, tears running down his face and his hands gripping his obviously swollen knee. He had gone with his best friend to the hospital, had sat with him as they listened to the diagnosis. Hell, he had even went with him to his physical therapy sessions. That first year of high school was spent making sure Oikawa didn't do anything stupid.

The second year was when Oikawa was finally able to shine. He and Iwaizumi had easily made it on the starting-line up. The two worked well together, so well that by the end of their second year, there was no doubt that Oikawa would be the captain with Iwaizumi as the vice-captain and ace. But it was also at the end of their second year that Iwaizumi heard a familiar name.

"So," Oikawa said, a scowl already on his face when he met up with Iwaizumi after practice. "Coach wants our input on new players next year…he wants us to go watch some of the junior high games."

Iwaizumi nodded, not surprised. He remembered previous captains and vice-captains doing so. He even remembered being watched when he was in junior high.

"Kitagawa Daiichi is doing well this year," Oikawa continued, his scowl growing even more fierce. "Coach asked that we take a particular look at their team…and their setter."

Iwaizumi kept his face blank, "Ah, that would be Kageyama, right?"

"Iwa-chan!" Oikawa groaned, pouting, "He can't come here! What if he-"

"Even if he got in, it doesn't mean he'll take your place," Iwaizumi said, mentally sighing at his best friend. "Let's just see how the games go."

Which is how Iwaizumi found himself staring in shock as every member of Kitagawa Daiichi turned their backs on the young setter. He had been in disbelief throughout the game, wondering how the sweet kid he had known had turned into…this in just two years. What had happened? When he had graduated, Kageyama had been quiet and a little awkward, but this was insane. It was obvious something had broken long before this game. Kageyama, Kindaichi, and Kunimi had been thick as thieves when he and Oikawa had left. He had felt safe leaving the team to them, knowing that the three of them would be an amazing and dangerous combination. How had that turned into this?

He hadn't protested when Oikawa told coach that he didn't think Kageyama would be a good fit for their team. He had merely nodded when Oikawa gave Kindaichi and Kunimi a recommendation. Why did he feel numb? Things happen, people change. It wasn't as if he had even really known the kid well. Why did he feel like this?

The new year came and with it so did Kindaichi and Kunimi. Iwaizumi greeted them warmly, took over their training much the way he had done in junior high. The two were faster now, and stronger, but both seemed to flinch whenever they missed a toss. Oikawa assured them over and over again that it was his fault, that they just needed to get used to each other, but it was obvious that the two didn't like to criticize the older setter.

Things quickly started to fall into place and before long, Kindaichi and Kunimi had both made their way onto the starting line. It wasn't until coach announced a practice match with Karasuno that Iwaizumi was once again forced to think of Kageyama. He knew that the entire reason for this practice game was because Oikawa had demanded it. Because Oikawa still had something to prove against Kageyama. Maybe he also thought that playing Kageyama would in some way help Kindaichi and Kunimi as well. But, of course, Oikawa ended up practicing too much and ended up spraining his ankle. He had been furious, not being able to play Kageyama. The doctor agreed to schedule a follow up appointment after school the day of the match. If cleared, Oikawa was hoping to make it before it ended.

Iwaizumi hadn't thought they would make it that long. Neither Kindaichi nor Kunimi had practiced much with Yahaba and it was obvious that their defense needed work, especially against Kageyama and his weird friend. Iwaizumi was growing more and more irritated. They were losing. Oikawa, who wanted the match in the first place, wasn't here. The team obviously still needed work. And Kageyama was refusing to look at him.

The two were standing on opposite sides of the net but every time Iwaizumi tried to catch his eye, Kageyama looked away. Iwaizumi was tempted to spike the ball at his head.

But then Oikawa showed up and Iwaizumi saw as his best friend taunted the younger boy. Well, taunted by Iwaizumi's standards. No doubt most of those around them just thought Oikawa was just greeting him with a friendly rivalry. Iwaizumi knew that very few of them saw the hard glint in Oikawa's eye.

They faded quickly in the final game. Yahaba, after seeing Oikawa walk into the gym, seemed to think that Oikawa would pick up the slack once he finally made it onto the court. Kindaichi and Kumini had been avoiding Kageyama's gaze the entire game, much like Kageyama had been avoiding his own, and it seemed to be throwing the two off. And that shrimp was faster than Iwaizumi liked to admit.

By the time Oikawa stepped onto the court, Iwaizumi wanted to hit something – most preferably his best friend. Said best friend seemed to think he would be able to come in, throw Karasuno off with his serves, and win them the game. But he hadn't counted on the shrimp by Kageyama's side. Iwaizumi would have laughed at the look on Oikawa's face when the ball flew right by him if he wasn't so irritated.

Somehow Kageyama disappeared before Iwaizumi was able to speak to him. He wasn't surprised when Kindaichi appeared only a few minutes later, seething. It wasn't long after that that Oikawa appeared. "Oi! We're supposed to be cleaning! Where have you been?"

"Just having a friendly chat," Oikawa replied. _Friendly my ass._

"Kageyama has become more amazing," Iwaizumi said, carefully watching his best friend who seemed to be nonchalantly tossing a volleyball.

"Yeah. That genius was spinning his wheels but finally found his best destination," Oikawa replied. Iwaizumi felt his eyes narrow at the unconcerned tone. "No commoner could hold a candle to him now."

"Yeah?" Iwaizumi said blankly, "You're no match for him either, then?"

"When it comes to the toss," Oikawa replied. "There's probably no one in the prefecture who could match Tobio's toss." Oikawa continued to play with the volleyball as Iwaizumi scowl fiercely. He turned away from his friend, walking toward the cart and picking up a ball. "But he's not better than me at serving, blocking, or spiking." Oikawa barely got the words out before Iwaizumi threw the ball at him, hitting him in the back. "Ouch!"

"Damn it, Oikawa! Don't say his toss is better than yours!" Iwaizumi snapped. "You're a setter, aren't you?" _Don't make me go through all this again._

"But I'm only being honest!" Oikawa said with a frown. "That's why we have to break their receivers. Because no matter how amazing his tosses are, if the ball doesn't get to the setter, it's all for nothing." Of course he was planning something. Iwaizumi should have known. There was no way Oikawa would let this go. "If we can play against Karasuno in an official game, we can make a mess out of their receives and not even give them a chance at a toss. Just having one good player doesn't mean you'll win. How I want to say 'don't mind' to them! How I want to say it."

Iwaizumi glared at the complete joy on his friends face. It always freaked him out slightly how sadistic Oikawa could be when he put his mind to it. "What?" Oikawa asked when seeing his scowl. "Don't geniuses piss you off?"

"Guys that girls squeal over piss me off even more," Iwaizumi said, remembering the loud screams that had echoed throughout the gym when Oikawa walked in. It had given him a headache and hadn't helped his mood. Iwaizumi threw yet another ball, hoping Oikawa would forget whatever he was planning for Karasuno. No matter what the kid had done in the past, he didn't deserve more of Oikawa's ire.

"You shouldn't be jealous, Iwa-chan! It's embarrassing!"

He did not just… Iwaizumi picked up another ball, hurling it toward his friend. Did he really think that was the issue?! "Hey! Quit fooling around! Coach'll get mad!" Someone yelled as Oikawa continued to whimper.

Iwaizumi didn't see Kageyama again until the Inter-High tournament. He had watched Karasuno's first game, amazed at the changes he saw. There was no doubt that Karasuno was a force to be reckoned with. Shorty had been irritating enough, now with an ace and libero, it was just going to be that much harder. But, at their practice match they hadn't had Oikawa.

Iwaizumi would never admit it, but Oikawa really did make the team better. He would never tell his best friend that, though. He'd never hear the end of it.

He had to admit, he was excited to play Karasuno again. With their new team members and Oikawa at full strength, it was sure to be a great match. Oikawa was convinced they were going to win, and Iwaizumi didn't doubt him, but he knew it would be harder than Oikawa thought.

He was right.

He had actually considered the possibility of not winning during their third match. The last game had seemed to go on forever, neither able to get that final match point. Whoever got to it first would win. He tried to imagine losing. To not going up against Ushijima again. To watching as someone else tried to win against him.

He didn't like it.

He was relieved when they won. To lose to Kageyama now would have broken Oikawa. Kageyama had time. There was no doubt in Iwaizumi's mind that Kageyama would one day take Karasuno to Nationals.

It just couldn't be now. Not this year. Not after all they been through.

Iwaizumi stripped of his soaked jersey as the next match started. He quickly changed and looked toward his best friend. He kept imagining Kageyama's face. He had looked devastated. It was the same look he had seen on Oikawa countless times. A look that was currently nowhere in sight. "'Even if one person is good, you can't win. Don't mind'," he said, looking at Oikawa impassively. "Isn't that what you were going to tell them?"

Oikawa didn't answer for a second, and when he did it wasn't what Iwaizumi expected. "But Karasuno had more than one strong player, didn't they?"

"You're really annoying," Iwaizumi scowled.

"How rude! Then end of that second set…when he was able to read my toss to you… I could tell that Tobio was trying to go from being a dictator to a decent king. Even if Tobio had stayed a dictator, he might still have tossed to the shrimp in the end," Iwaizumi couldn't help but stare at his unusually sober best friend. "I only thought it was a possibility and there was no guarantee he was going to do it. He was reading my attacks, but this time, he ended up having his attacks being read by me."

"So Kageyama has finally started trusting other people…" Iwaizumi said, feeling a smile tug at the corner of his mouth.

Oikawa scowled, "Really…nothing could be more troublesome."

Iwaizumi let out a deep sigh at the look on his friends face, "You really are a crappy guy."

"Don't call me that!"

"Why does it matter? We won."

"But will we next time? It was close today, Iwa-chan! Too close! What will Karasuno learn between then and now? And if Tobio continues to evolve…"

"Seriously, Oikawa," Iwaizumi muttered, moving away from his friend. "You have got to let the Kageyama thing go."

It was months later that things finally fell into place for Iwaizumi. He was talking to Kindaichi about a possible practice match before Spring High Tournament when the junior asked if one of those matches would be against Karasuno.

"I haven't heard of us doing another practice match with Karasuno," Iwaizumi answered. "I think I heard something about them practicing with a school from Tokyo…?"

Kindaichi looked relieved, "Good. It's always so awkward…"

Iwaizumi nodded, thinking of the odd tension between Oikawa and Kageyama and between Kindaichi, Kunimi, and Kageyama. He had never really discussed it with Kindaichi or Kunimi. He had to admit he was curious. Something must have happened that broke their friendship. But if they weren't going to tell him, he wasn't going to pry. "I guess it's more awkward for you," Kindaichi said sheepishly. "Sorry."

 _What?_

"Why would it be more awkward for me?" Iwaizumi asked, "I mean, yeah, there's some…hostility between him and Oikawa, but that isn't really my problem."

Kindaichi stared at him, eyes wide. "You and Oikawa? I mean, I knew you two were close but I didn't know you were…"

He trailed off and Iwaizumi felt that he was completely missing a vital part of this conversation. "Well, Oikawa and I have always been close," he said carefully.

Kindaichi shifted anxiously, "But, I mean, what about Oikawa's soulmate?" he blurted. Then he immediately looked contrite. "Sorry, sorry, none of my business."

Now Iwaizumi was really confused. "What does Oikawa's soulmate have to do anything? Wait," he said suddenly feeling the urge to punch his best friend, "did Oikawa find his soulmate and not tell me?"

"Wh-no! I mean, not that I know of. I just, well, shouldn't they be a…topic…?"

"What the hell does Oikawa's soulmate have to do with me? Or Kageyama?" Iwaizumi demanded, finally fed up with whatever odd conversation he was having. "I mean, Kageyama isn't Oikawa's soulmate, is he?" As he spoke, the words seemed to sink into his skin and he shivered at the icy coldness. What a mess that would be. But didn't Kindaichi just say Oikawa hadn't found his soulmate?

"What?" Kindaichi said, his own brow furrowed in confusion. "No – I mean, that would probably make things less complicated for you," he said, breaking off and suddenly looking thoughtful, "I mean if the three of you were bonded."

 _Three of you?_

 _THREE of you?_

 _What a-_

"Kindaichi," Iwaizumi said, his voice carefully controlled which completely differed from the current emotions raging within him. "What exactly are you talking about?"

There was that frown again. "Well, if Oikawa was also your soulmate, you wouldn't have had to choose. I know that doesn't…"

Iwaizumi knew that Kindaichi was still talking but he was unable to hear him. _Was_ ALSO _your soulmate?_ Choose? That couldn't be…Kindaichi couldn't be saying what Iwaizumi thought he was saying. That wasn't…wasn't possible. He would know, wouldn't he?

"How do you know?" Iwaizumi said, his voice sounding rough even to his own ears. Kindaichi cut off from whatever he had been saying and looked worried for the first time since the conversation started.

"Sorry, was I not supposed to? Did you not want people to know? I mean, Kunimi and I were there that day Oikawa confronted him about it. Maybe he didn't notice us? Or maybe he forgot to tell you we were there?"

 _…that day Oikawa confronted him about it…._

"Oh, I think Oikawa forgot to mention a lot of things," Iwaizumi growled, his eyes scanning the gym for his best friend. Well, his once best friend. Iwaizumi was pretty sure he was going to kill him. "Kindaichi, I have to go," he said as he finally spotted Oikawa talking to Yahaba.

"O-okay."

Iwaizumi stormed over toward Oikawa, grabbed his best friend by the arm, and began to haul him out of the gym. He heard Oikawa squawk and then complain about "manhandling him!", but Iwaizumi was too furious to care. He let the gym doors slam as he pushed Oikawa in front of him. "I'm going to ask you a question and I want the truth," Iwaizumi said, his hands clenching at his sides.

Oikawa, for once, didn't complain as he looked at Iwaizumi. Iwaizumi watched as Oikawa swallowed hard and nodded his head once, his eyes completely serious. "Is Kageyama my soulmate?"

Oikawa lost all color at the question. He opened his mouth but no words made their way out. His hands clenched and unclenched at his sides. Iwaizumi watched, completely unaffected, as Oikawa's eyes turned red as tears welled in them.

It was true then. Just looking at Oikawa was answer enough.

"Why?!" He asked, his voice coming out quieter than he had intended. "Why would you…what the hell?!"

"Iwa…Iwa-chan, listen," Oikawa whispered, his voice wavering. "I shouldn't – I know I shouldn't-" but Iwaizumi wasn't listening. He turned, walking toward the school gates. He couldn't believe this. What the hell was going on? Oikawa wouldn't have done that to him. Not to him! Not after everything. "Hajime!" Oikawa yelled desperately, running up to follow him and grabbing onto his arm. Iwaizumi tugged it away, not caring as Oikawa tried to regain his hold. "Listen! I was just so upset when I saw it! I just kept thinking that he would take you away the same way he was taking everything else! I know I shouldn't have done it – I know I should have told you! I'm sorry! Please don't –"

Iwaizumi pulled away once again, letting Oikawa curl into himself, his arms around his stomach as he choked on his sobs. For the first time, Iwaizumi didn't care. He left him there, crying, as he continued down the street. _"I was so upset when I saw it…"_

All those errands he had to run. He was always later to practice than everyone else. He didn't change in front of them. He wouldn't have seen.

 _"Kunimi and I were there…"_

Oikawa telling the other third years to practice with the first years while Iwaizumi practiced with him.

 _"Take you away the same way he was taking everything else."_

Oikawa's furious, jealous gaze on Kageyama. Iwaizumi grabbing his best friend and stepping between the two before Oikawa was able to lash out.

 _"He will pass me and take everything away! I can't let him do that, Iwa-chan! He can't take it away!"_

Those words from years ago. That night Oikawa had come to his room. Was that it? Was that the day Oikawa had realized?

Was that the day his best friend began lying to him?

He wasn't sure how long he had been walking until he found himself in front of Karasuno. What had Oikawa said to Kageyama? If Kageyama knew, why hadn't he said anything? Was that the reason he had always avoided Iwaizumi whenever they saw each other? Did whatever happen that day contribute to the change in Kageyama? Or his break in friendship with Kindaichi and Kumini?

It didn't take Iwaizumi long to find his way to the gym. He stepped in the doorway and watched as Karasuno played, Kageyama and the shrimp's team against the older setter and the ace. Iwaizumi noticed that the older setter also had the libero, though Kageyama had the captain. He had been there a few minutes when the tall middle blocker saw him. He instantly dropped his arms and stared as the shrimp cheered when his spike flew past him. "Ooh, that's another one, Tsukishima! I'm winning!" The shrimp taunted.

But the tall middle blocker didn't retort. "King, I think you're wanted," the blonde drawled, lazily pointing toward the door.

Kageyama, as well as the rest of the team and coach, turned toward the door. Kageyama blinked in shock while the shrimp squawked loudly. "Aobajosai's ace!"

Iwaizumi turned to Karasuno's coach and bowed, "Sorry to interrupt practice. Do you mind if I speak to Kageyama for a moment?"

"Uh, sure," the coach said after a pause, clearly not sure what to say. "Uh, Kageyama, go ahead."

Kageyma looked as if he was going to protest. He glanced at Iwaizumi for a moment before letting his shoulders slump and move toward the door. "What are you doing here?" He asked. Iwaizumi didn't respond, instead turning to make sure the door was firmly closed. He really didn't want an audience for this conversation.

"Why didn't you tell me our marks matched?"

Iwaizumi watched as Kageyama's face went slack. He blinked frantically for a moment, as if trying to comprehend the words Iwaizumi had spoken, before his brow furrowed in confusion. "I – what?"

Yeah, this was more like the first year Iwaizumi remembered.

"I just found out that, apparently, your mark matches mine. And, since Kindaichi seems to think I know about it, I'm asking you why I don't."

Kageyama just continued to stare at him. Iwaizumi, who was growing more and more impatient and was trying to hold back the surge of anger he still had in chest, scowled fiercely. "Look, I don't know why you-"

"What do you mean you didn't know?!" Kageyama finally growled, taking a step forward with his own hands clenched into fists. Iwaizumi blinked in surprise. "I did tell you! I put that note in your locker and you had Oikawa-"

"What note?"

Kageyama broke off, his face completely blank. His eyes seemed to fly over Iwaizumi's face. "You really don't know."

"What the hell are you talking about?"

Kageyama let out a deep sigh, running his hand over his face. "I-how do you – come on," he finally muttered, moving further away from the gym. Iwaizumi frowned but didn't get to ask the question before there was an answer, "A closed door isn't going to stop them if they want to know what's going on."

Well, okay then. Iwaizumi looked at the closed door suspiciously before following the younger to a more secluded area. Kageyama stopped, his back facing Iwaizumi. "I – saw your mark shortly after I joined," Kageyama admitted, his voice muffled since he was facing away. "I thought you would say something, but I realized you hadn't noticed. I didn't want to bring it up, so I wrote a note instead."

"Which you put in my locker," Iwaizumi said in realization.

"Oikawa told me the next day that you didn't want someone like me for a soulmate and you thought it would be better if we stayed away from each other. Then you stopped coming into the clubroom and Yama-senpai took over working with us…"

He was going to kill Oikawa.

"I didn't get the note," Iwaizumi said, taking a step closer but stopping when he saw Kageyama's shoulders tense. "Look, I don't know when you put it in there, but Oikawa and I shared a locker most of the time because his was full of crap. He never told me. Well, not until about twenty minutes ago, anyway."

There was silence for just a moment before Kageyama turned around, his eyes red. "You really didn't…?"

"I didn't know," Iwaizumi confirmed, taking yet another step and feeling slightly relieved when the other boy didn't tense. "Look, this is just…a mess. I kind of want to kill Oikawa, but I understand why he did it. Even if he had no right to."

Kageyama scowled, "He-"

"Has surprisingly low self-esteem. He somehow convinced himself that I would stop speaking to him if I found out about our marks…well, at the moment, I really am not speaking to him, but not because of that…"

"What do we-" Kageyama broke off, looking frustrated with himself. Iwaizumi watched, slightly fascinated, as a bright blush slowly spread across the younger boy's face. "I mean…"

"Look, we haven't really talked in years," Iwaizumi said, guilt hitting him at the words. "I think we should kind of…start over? Get to know each other? I mean, we really didn't know each other well in the first place. I know how you play volleyball. I know you're great at volleyball. But outside of that…"

Kageyama slowly nodded, his expression pinched. "I – yeah. Okay."

Feeling his lips tug upward, Iwaizumi extracted his phone and held it out to the other boy. "Number?"

The blush deepened, but Kageyama quickly took the phone and entered his contact information. "Look, Kageyama," Iwaizumi said as he placed his phone back in his pocket. "I have to be honest. Oikawa's a shitty person and what he did was horrible…but he's been my best friend since we were four. He's going to do a lot of groveling and he's going to apologize, to both of us, but he's still my best friend. Can you two at least try? Not now, but eventually?"

For a moment, Iwaizumi thought he had gone too far. Kageyama looked as if he was seriously contemplating leaving right then. But, finally, Iwaizumi received a single nod in response and he felt a smile overtake his face.


End file.
